Rorippa sylvestris (L.) Besser
Glabrous perennial rhizomatous herb. Stems erect, often flexuous, 30-70 cm tall. Lvs variable in shape; margins toothed. Rosette lvs petiolate, auriculate at base, deeply pinnatifid, 4-10-(25) × 2-4 cm. Middle and upper lvs smaller, 1-2-pinnatifid, linear to ovate; lobes narrow-lanceolate to linear, entire or toothed; basal auricles present. Pedicels erecto-patent at flowering, spreading at fruiting, 5-15 mm long. Sepals 2-2.5 mm long. Petals yellow, (3)-4-5 mm long. Silique glabrous, linear, curved, 10-15 × 1-1.5 mm, but often not or poorly developed; valves with median vein weak or 0; style c. 0.5 mm long. Seeds brown, c. 0.6 mm long, finely colliculate, in 2 rows per locule.
N.; S.: locally common throughout.
Temperate Eurasia 1952
Gardens, market gardens, cultivated and swampy land, riverbeds and damp pasture.
FL (Oct)-Dec-Feb-(Mar) Dec-Feb-(Mar).
R. sylvestris, like R. amphibia, is self-incompatible and colonies of only one genotype are often established. In such cases the plants do not set seed.